A variational adiabatic hyperspherical finite element R matrix methodology: general formalism and application to H + H reaction.

The aim of this paper is to present an efficient numerical procedure for the theoretical study of bimolecular reactions. It is based on the R matrix variational formalism and the p-version of the finite element method (p-FEM) for expanding the wave function in a finite basis set, and facilitates the development of an efficient algorithm to invert matrices that significantly reduces the computational time in R matrix calculations. We also utilise the self-consistent finite element method to optimise the elements mesh and provide faster convergence of results. We apply our methodology to the study of the collinear H + H process and evaluate its efficiency by comparing our results with several results previously published in the literature. [ABSTRACT FROM AUTHOR]